Block connections above 50mbps

Is there any way to block connections wich uses more then 50mbps? (floods)
Because my server keeps getting dossed wich 60-70mbps floods... and i already manually kept blocking those ip's for like the whole day now

Some more info:
I'm running a cod4 server on it, so it gets alot of connections but those are 40-50kbps each, i don't want to block those